When should I access properties with self in swift?

Question

In a simple example like this, I can omit self for referencing backgroundLayer because it\'s unambiguous which backgroundLayer the backgroundColor is set on.

Answer 1

As Nick said, in objective-c we had ivars + synthesized properties which gave the _internal variable names to delineate things. Eg.

@IBOutlet (nonatomic,strong) UITableView *myTableView;

resulting in _myTableView to be (preferably) referenced internally - and self.myTableView to be reference beyond the class. While this is pretty black and white, consider the exception when programmatically instantiating views, you can gain clarity/ simplicity / reduce boilerplate by removing self.

@interface CustomVC:UIViewController
{
     UITableView *myTableView; 
}

In swift, the public / internal properties clarify this scope. If it's a public property that other classes will interact with err on self. Otherwise if it's internal skip self and avoid the automatic repetition. The compiler will catch you when it's needed.

// UIViewcontroller swift header
public var title: String? // Localized title for use by a parent controller.
public var navigationItem: UINavigationItem { get } 

/// In your class
self.title  = "Clarity"
self.navigationItem.leftBarButtonItem = UIBarButtonItem()

// In superclass  
 @property(nonatomic, copy) NSString *screenName  // use self.screenName in swift subclass

@IBOutlet myTableView:UITableView  // use self
public var myTableView:UITableView  // use self

internal var myTableView:UITableView // skip self
var myTableView:UITableView // skip self